1. Field of the Invention
The present invention relates to a line synchronizing apparatus capable of following such as a variety of works or assembly parts moving along a roller conveyer line.
2. Brief Description of the Prior Art
As an apparatus for providing an operation such as tightening or the like, in sychronization with a work moving along a production line, it is known a "Line Synchronization Apparatus" as disclosed in Japanese laid-open patent publication No. 62-153019 (Application No. 61-39794, 1986). Such an apparatus includes a synchronizing means disposed over and in parallel with a transport line and suspended downwardly therefrom; fastening means such as a nut runner provided on the lower side of the synchronizing means; and, in addition, engagement means provided on the lower end of the synchronizing means: whereby, as the work is conveyed along the line, the engagement means is lowered to engage with the work, the synchronizing means is turned to its operation condition, and therefore the synchronizing means, driven by the conveying force of the line, also travels following the work. Subsequently, the nut runner port is lowered to perform tightening operation during moving of the work.
However, there were problems in the foregoing construction, in the case that a roller conveyer is used as the conveyer. In such a case, the transport of the work is achieved by friction between surfaces of the roller and the work. On the other hand, the synchronizing means is formed to include therein a drive system for the fastening means, control means and also a housing structure therefor, thereby having a dimension of a large scale and of a heavy weight. Accordingly, especially in the case of a work having a light weight such as formed of aluminum, the friction between the rail and the synchronizing means is sometimes of a value very close to that between the roller and the work, and therefore the work would be undesirably kept as being untransported to cause trouble in the operation of the subsequent process.